For example, if your hygrometer reads 70% during the salt method test this means that to obtain the real humidity level you should add 5 points. If you have an analog hygrometer, turn the knob to adjust it to 75 percent. If you have an analog hygrometer, you can correct the reading. Calibrating digital and analog hygrometers are actually very easy. The hygrometer should read 75%. Analog hygrometers are manufactured with a factory tolerance of +/- 5% points of humidity (and sometimes more) through the normal range of 40-80%. To check if your analog hygrometer is reading correctly, use the salt method to test it’s accuracy. Place about 1 teaspoon of salt in a small shallow open container, such as the cap to a jar. After an hour, you have to adjustthe hygrometer on the rear with a screwdriver to 96% rel. You need to wrap the hygrometer in a thoroughly moistened cloth and then wait for an hour. The difference is how much your hygrometer is off. If your hygrometer is reading below or above 75%, you will need to adjust the reading to register 75%. For example, if your hygrometer reads 70% during the salt method test this means that to obtain the real humidity level you should add 5 points. The difference is how much your hygrometer is off. For species that like 70-85% RH use damp salt in a bowl placed in a ziplock bag with the hygrometer. Analog / Dial Hygrometer. Analog hygrometer calibration is not so different from calibration a digital hygrometer, but there are a few differences here and there. Analog hygrometers, while cool looking, are notorious for inaccurate readings. If you have an analog hygrometer, you can correct the reading. Although humidity gauge is pre-set at the factory, its calibration may be off within this range for various reasons. Calibrate Your Hygrometer Using The Salt Method. These hygrometers require regular calibration and maintenance more than digital ones do. How To Calibrate an Analog Hygrometer. For most analog hygrometers, simply adjust the needle to read 75% on the gauge by turning the screw on the back of the hygrometer with a small screwdriver. Below are the steps. The most effective method of calibration for hygrometers, be it digital or analog, is the use of a salt paste. Place some salt in a bottle cap or small cup and dampen it with a few drops of water with out dissolving it. humidity. Calibrating a digital or analog hygrometer Calibrate your hygrometer to the application. With that said, here are two main tips of what needs to be done for calibrating your hygrometer: Table Salt Method. So you purchased a humidor, seasoned it, and you are ready to load in your cigars. The hygrometer should read 75%. If you have a digital hygrometer, use the buttons to adjust it to 75 percent. If your hygrometer shows a humidity lower or higher than 75 percent, you'll need to calibrate it so that it's accurate when you use it to check the humidity of your humidor. Many digital hygrometers can be adjusted with a button. Another way to test calibrate the analog hygrometer is through removing the hygrometer from the humidor. The hygrometer should should read 75%. This is carried out by following the following steps: Analog (dial-type) hygrometers are often shipped from the factory out of spec. If you chose to use an analog version, know that you should recalibrate your hygrometer at least once every two months to be sure you are getting an accurate measure of humidity. To calibrate, you need plain table salt, a few drops of water and a see-through Tupperware container with a tightly fitting lid. Follow this step by step method for the perfect calibration.